I was down in Melbourne recently talking with a friend. She told me about a documentary she had seen about intermittent fasting. We were talking about life being too short I think and needing to be able to live longer to fit everything in. This particular documentary discussed a little about that which is what got us onto the topic.

It has been found that even in higher order mammals like rats and mice that calorie restriction can result in up to 40% ore more increase in life span. To put it in perspective if you would ordinarily live to 80 years, on calorie restiction you would live to 112 years. Whats more you do so with less heart disease and much fewer cancers.

I had recently been looking into the effect of calorie restriction on rats as my own rats, which have free access to food and can therefore eat as much as they want, whenever they want, were getting very obese, to the point that they developed ulcers on their hind feet. The vet suggested that I should restrict their access to food to reduce their weight.

Few researchers keep rats for as long as us but I did come across one paper that followed three groups of rats for two years. One group of rats aere fed ad lib (ie as much as they wanted, whenever they wanted, just like ours), another group were fed only 75% of what a normal rat would eat in a day, and a third group was fed 45% of what a rat would ordinarily eat in a day. The longevity and other effects were proportional to the amout of calorie restriction, in other words the rats on the 45% diet have more pronounced changes than the less restricted rats.

In addition to leading to the rats living longer the calorie restriction also resulted in fewer tumors. Over time, a proportion of rats will develop tumors through out their lives just as we do, it appears that calorie restriction reduces the incidence of tumor development, which is also a problem we had been having in our rats.

Rats that just ate however much they wanted, whenever they wanted, according to this study, resulted in 28 times more neoplasms than their kilojoule restricted counter parts and have a 100% higher mortality rate at two years of age (Hubert MF. Laroque P. Gillet JP. Keenan KP. The effects of diet, ad Libitum feeding, and moderate and severe dietary restriction on body weight, survival, clinical pathology parameters, and cause of death in control Sprague-Dawley rats. Toxicological Sciences. 58(1):195-207, 2000).

Anyway my friend and I got to talking about this and she mentioned the documentary she had seen about a medically trained documentary film maker who had examined several protocols for intermediate fasting himself and examed the effects over 8 weeks. While he described results over a relatively short period and so could not therefore describe the effect on his longevity, he found that he lost weight and several measures in his blood chemistry were reduced which is consistent with a reduced risk of diabetes and heart disease.

The point of this particular documentary was that you don’t need to be on a severely calorie restricted diet for your entire life to obtain some of the benifits of a calorie restricted diet, but the same result appears to occur with only periodic calorie restriction, ie periodic or intermittent fasting. This story was taken up by the press and reported as the 5:2 diet as you eat what you want for five days of the week and eat 25% of the recommended intake for two days of the week. The popular press generally focusses on the weight loss or diet aspect of this story, but the reduced incidence of cancer, better cardiac health and longer life span was also of interest to me.

This documentary film maker ended up putting out a book about his story called the Fast Diet (http://www.angusrobertson.com.au/book/the-fast-diet-the-secret-of-intermittent-fasting-lose-weight-stay-healthy-live-longer/38986270/?gclid=CJCP5qj1n7wCFUgHvAodqXMADQ), and this same friend bought it for me for my birthday just done. I decided I might do my own study as my body mass index is 26, so I am a little over weight, and as I say I wouldn’t say no to a postential extra 30 years of life.

I have made an appointment with the Univeristy Health Clinic to get a metabolic blood screen done before I start so that we have some baseline data to compare it to. But I will post how things are going and what I find out here about my experiences with intermittent fasting.